21352872 has 16 divisors (see below), whose sum is σ = 53382240. Its totient is φ = 7117616.

The previous prime is 21352861. The next prime is 21352883. The reversal of 21352872 is 27825312.

It is an interprime number because it is at equal distance from previous prime (21352861) and next prime (21352883).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 444828 + ... + 444875.

It is an arithmetic number, because the mean of its divisors is an integer number (3336390).

Almost surely, 2^21352872 is an apocalyptic number.

It is an amenable number.

21352872 is an abundant number, since it is smaller than the sum of its proper divisors (32029368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21352872 is a wasteful number, since it uses less digits than its factorization.

21352872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 889712 (or 889708 counting only the distinct ones).

The product of its digits is 6720, while the sum is 30.

The square root of 21352872 is about 4620.9167921528. The cubic root of 21352872 is about 277.4291548717.

The spelling of 21352872 in words is "twenty-one million, three hundred fifty-two thousand, eight hundred seventy-two".